Pile hammer

ABSTRACT

A pile hammer includes a cylinder, a piston displaceably guided in the cylinder, a striker displaceably guided in the cylinder and disposed underneath the piston in the operating position of the pile hammer, a combustion chamber delimited axially by a face surface of the striker that lies in the interior of the cylinder and by a face surface of the piston, as well as a disengagement apparatus by way of which the piston can be moved in the cylinder, into an upper position, wherein the disengagement apparatus includes a carriage, which is connected with at least one cable, by way of which the carriage is guided to be displaceable on the outside, along the cylinder, wherein a stop that projects outward is disposed on the cylinder and a buffer part is disposed on the carriage, with which part the carriage lies against the stop in an upper end position.

CROSS REFERENCE TO RELATED APPLICATIONS

Applicant claims priority under 35 U.S.C. §119 of European Application No. 14184318.5 filed Sep. 10, 2014, the disclosure of which is incorporated by reference.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The invention relates to a pile hammer comprising a cylinder, a piston displaceably guided in the cylinder, a striker displaceably guided in the cylinder, which striker is disposed below the piston in the operating position of the pile hammer, a combustion chamber that is delimited axially by a face surface of the striker that lies in the interior of the cylinder and a face surface of the piston, as well as a disengagement apparatus by way of which the piston can be moved in the cylinder, into an upper position.

2. Description of the Related Art

Such pile hammers, such as diesel hammers, which are also called diesel pile drivers, are particularly used in foundation work in the construction industry. The pile hammers are used for driving posts of all kinds, such as concrete pillars, iron beams, sheet pile wall elements or the like into a construction ground.

During the starting procedure of such a pile-driving device, a piston is pulled upward within a cylinder, using a disengagement apparatus, and released at a defined height, thereupon dropping downward under the effect of gravity. As it drops, the piston activates a fuel pump, thereby conveying fuel into the working chamber of the cylinder of the pile-driving device.

By the downward movement of the piston within the cylinder of the pile-driving device, the air present in the working chamber of the cylinder is compressed and heated to such an extent that the fuel/air mixture present in the working chamber is ignited, whereupon it combusts in the manner of an explosion. The impact of the piston onto the striker initiates not only the ignition of the fuel/air mixture but also the transfer of drop energy into the material to be pile-driven. Because of the explosion energy released during this process, the piston is accelerated upward for a new work cycle. At the same time, the material being pile-driven is driven into the ground. As the piston rises, exhaust openings are exposed, so that combustion gases can escape and the pressure in the cylinder space becomes equal to the ambient pressure once again.

In the case of pile-driving locations that are difficult to access, particularly in the case of off-shore applications, the pile hammer is regularly positioned at the pile-driving location by way of cables, directly or also by way of an attached leader that surrounds it. For this purpose, the pile hammer or also the attached leader that surrounds it is attached by means of two cables disposed to lie opposite one another, which are connected with a traverse that in turn is connected with the crane cable of a crane. Furthermore, a center cable is also disposed on this traverse, which cable is connected with the carriage of the disengagement apparatus of the pile hammer. In this manner, single-cable handling of the pile hammer on the crane side is made possible.

It is a disadvantage of the previously known pile hammer that when the pile hammer is set up from a horizontal position by way of the crane cable, it can occur that the outer holding cables come to lie around the guide rails of the disengagement apparatus, which rails can be damaged when these cables are pulled. Furthermore, it can occur that in the case of disadvantageous positioning of the cables, the main weight of the pile hammer lies on the center cable connected with the disengagement apparatus, thereby resulting in damage to the disengagement apparatus. Furthermore, damage to the center cable, which is not designed for such stresses, can occur. Last but not least, the center cable arrangement proves to be problematic in the case of the previously known single-cable handling on the crane side, because a pendulum movement of the pile hammer is caused by the tensile force applied to the disengagement apparatus by way of the center cable. This movement can have a negative effect on the beginning of the pile-driving process.

SUMMARY OF THE INVENTION

The invention wishes to provide a remedy for this situation. The invention is based on the task of making available a pile hammer that allows single-cable handling on the crane side particularly also in the case of off-shore applications, and in which damage caused by raising of the pile hammer by way of a crane cable is prevented. According to the invention, this task is accomplished by means of a pile hammer including a cylinder, a piston displaceably guided in the cylinder, and a striker displaceably guided in the cylinder. The striker is disposed underneath the piston in the operating position of the pile hammer. A combustion chamber is delimited axially by a face surface of the striker that lies in the interior of the cylinder and by a face surface of the piston. A disengagement apparatus, by way of which the piston can be moved in the cylinder, into an upper position, includes a carriage, which is connected with at least one cable, by way of which the carriage is guided to be displaceable on the outside, along the cylinder. A stop that projects outward is disposed on the cylinder, and a buffer part is disposed on the carriage, with which part the carriage lies against the stop in an upper end position.

With the invention, a pile hammer is made available that allows single-cable handling on the crane side particularly also in the case of off-shore applications, and in which damage caused by raising of the pile hammer by way of a crane cable is prevented. Because the carriage of the disengagement apparatus is connected with a cable, by way of which the carriage is guided to be displaceable on the outside, along the cylinder, wherein a stop that projects outward is disposed on the cylinder, against which stop a buffer part disposed on the carriage lies in an upper end position, direct transfer of the tensile forces to the stop by means of the buffer part is brought about, thereby guaranteeing damage-free lifting of the pile hammer. This at least one cable serves to both set up and position the pile hammer by way of a crane cable, and to control the disengagement apparatus for lifting the piston guided within the cylinder of the pile hammer.

In a further development of the invention, the at least one cable is guided between at least one pair of guide rollers disposed on the cylinder. In this way, introduction of the tensile forces directed orthogonally at the stop, by way of the buffer part, is made possible. In the event that the pile hammer is disposed in an attached leader, the at least one cable is guided between at least one pair of guide rollers disposed on the attached leader.

In a further embodiment of the invention, the axes of the guide rollers of the at least one pair of guide rollers are disposed on a line parallel to the center axis or center of gravity axis of the cylinder. In this way, perpendicular guidance of the pile hammer during raising and positioning is made possible. In this connection, the guide rollers of the at least one pair of guide rollers are preferably disposed and dimensioned in such a manner that in the vertical position of the cylinder, the at least one cable, in the tensed state, runs offset in the direction of the center axis or the center of gravity axis of the cylinder, or, particularly preferably, runs through the guide rollers in the tensed state, on the extended center axis or center of gravity axis of the cylinder. In this case, unintentional tilting of the pile hammer during raising and positioning is avoided.

In a further development of the invention, a guide anchor is disposed on the carriage, around which anchor a cable is passed. This cable is guided on both sides of the guide anchor, between two guide rollers, in each instance, disposed on the cylinder or on the attached leader, at a distance from one another. In this way, handling of the pile hammer during raising and positioning is further improved. In this connection, the guide anchor is preferably disposed orthogonal to the longitudinal center axis of the carriage.

In an embodiment of the invention, the guide rollers of the pairs of guide rollers have a radially circumferential guide groove, in each instance, to accommodate the cable, which groove aligns with the guidance of the guide anchor. In this way, offset-free guidance of the cable is brought about. In the tensed state of the cable before raising of the horizontally disposed pile hammer, guided, offset-free cable deflection by 90 degrees is brought about in this way.

In a further embodiment of the invention, the buffer part is configured to be elastic, at least in certain regions, and/or elastically mounted on the carriage. In this way, a gentle impact of the buffer body against the stop is brought about when the at least one cable is tensed.

In a further embodiment of the invention, the cable that runs around the guide anchor is connected with a traverse at its two ends, which traverse has an accommodation for a crane cable. In this way, optimal single-cable handling by way of the crane cable of a crane is made possible. Preferably, the accommodation is formed by a shackle for accommodating a crane hook.

In a further embodiment of the invention, the stop that projects outward has a contact piece that projects beyond the carriage of the disengagement apparatus. In this way, damage to the carriage is prevented when the pile hammer is laid down horizontally.

In a further development of the invention, a further contact part is disposed on the pile hammer, on its end directed opposite the carriage, parallel to the contact piece, which part preferably is formed as a roller body. In this way, a further support body is formed for laying the pile hammer down horizontally, by way of which body setting up the pile hammer into the vertical position, by way of the at least one cable, is made possible at the same time. Furthermore, a contact part configured as a roller body allows rolling the pile hammer over the ground while the opposite end is raised.

BRIEF DESCRIPTION OF THE DRAWINGS

Other objects and features of the invention will become apparent from the following detailed description considered in connection with the accompanying drawings. It is to be understood, however, that the drawings are designed as an illustration only and not as a definition of the limits of the invention.

In the drawings, wherein similar reference characters denote similar elements throughout the several views:

FIG. 1 is a schematic representation of a pile hammer;

FIG. 2 is a representation of the pile hammer from FIG. 1 in a side view;

FIG. 3 is a detail view of Detail A of the representation from FIG. 1;

FIG. 4 is a representation of the pile hammer from FIG. 1 in horizontal position, before the setting up process, with the cable positioning indicated in a detail representation; and

FIG. 5 is a representation of the guide anchor of the pile hammer from FIG. 1

a) in a top view; b) in a side view; c) in the detail section A-A.

DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS

Referring now in detail to the drawings, the pile hammer shown in FIGS. 1 and 2 selected as an exemplary, embodiment is configured as a diesel hammer 1. The diesel hammer 1 has a cylinder 2 that is open on both sides, and regularly can have a length of 3 to 8 meters and a diameter of 0.2 to 1.5 meters. A piston—not shown—is displaceably disposed in the cylinder. A striker 3 coaxial to the piston engages into the open lower end of the cylinder 2, in displaceable manner. A striker plate 31 is formed onto the striker 3; its lower delimitation surface, directed outward, interacts with the upper end of a concrete pillar to be pile-driven during operation. In the exemplary embodiment, a pile ram chisel 4 for accommodating material to be pile-driven is disposed below the striker plate 31.

Two guide spars 21 are attached on the outside of the cylinder, parallel to one another, on which the carriage 51 of a disengagement apparatus 5 is guided so as to be displaceable.

The carriage 51 of the disengagement apparatus 5 comprises two guide arms 52, disposed parallel to one another, which are connected with one another by way of a center brace 53. See FIG. 3. An entrainment hook—not shown—that projects into the cylinder 2 is attached to the center brace 53, to raise the piston—not shown. At its end that lies opposite the pile ram chisel 4, a guide anchor 54 is attached to the center brace 53 so as to lie transverse to it. The guide anchor 54, which serves for connecting the carriage 51 with a cable, is configured to be rounded off at its two ends, and is provided with a depression 541 (see FIG. 5) for accommodating and guiding the cable 7.

A groove 542 for accommodating a locking element—not shown—is introduced into the center of the guide anchor 54, in the depression 541; the cable 7 is provided with this element. The cable is fixed in place within the guide anchor by means of the locking element fixed in place in the groove.

Alternatively, two cables can also be attached on the two sides of the guide anchor 54, in place of the circumferential cable 7. Two guide plates 543 are disposed on the two sides of the depression 541, on the guide anchor 54, parallel to one another, between which plates spacer sleeves 544 are disposed, by means of which sleeves the guide plates 543 are connected and spaced apart from one another, by means of screws 545.

Two bores 546 that align with one another are introduced into the guide plates 543, lying opposite the buffer part 55. The bores 546 serve to accommodate a pin—not shown—for a connection with the center brace 53 of the carriage 51.

On the top of the guide anchor 54, which top lies opposite the center brace 53, a buffer part 55 that narrows upward is formed on, with an elastic damping piece 56 disposed on its free end.

A cylinder attachment 6 is disposed on the cylinder 2, by way of which the cylinder 2 is extended and on which two pairs 61 of rollers are disposed opposite one another. In this connection, the pairs 61 of rollers are disposed in such a manner that they align with the two ends of the guide anchor 54, so that it is made possible for the two cable ends passed through the pairs 61 of rollers on both sides of the guide anchor 54 to be accommodated and passed through without hindrance. The two rollers 611 of the pairs 61 of rollers are dimensioned and positioned in such a manner that the two cable ends of the cable 7 are passed through between the related pair 61 of rollers from the respective end of the guide anchor 54, in S shape, in such a manner that the cable runs parallel to the center axis of the cylinder 2 in the tensed state. The two cable ends of the cable 7 as well as the imaginary extended center axis of the cylinder 2 are thereby disposed on a common imaginary plane. With this cable guidance, optimally balanced handling of the diesel hammer 1 by way of a crane cable 71 (FIG. 4) is made possible.

A stop 62 that projects outward is formed on below the cylinder attachment 6, which stop projects beyond the carriage 51 of the disengagement apparatus 5. The stop 62 is provided with a contact piece 63. A roller body 22 is disposed on the diesel hammer 1, at its end directed opposite to the cylinder attachment 6, parallel to the contact piece 63. Alternatively, the stop 6 can also be disposed on the cylinder attachment 6.

In FIG. 4, the diesel hammer 1 is shown lying horizontally on the ground 9. In this connection, the diesel hammer 1 lies on the ground 9 only with the contact piece 63 and with the roller body 22. To set the diesel hammer 1 up, the crane cable 71 indicated with an arrow in FIG. 4 is connected with the shackle 81 of the traverse 8 and subsequently tightened, wherein the two ends of the cable 7 connected with the traverse 8 are tensed. The cable 7 thereby lies against the lower roller 611 of the respective assigned pair 61 of rollers, so that cable deflection by about 90° is applied. The guide anchor 54 that is connected with the carriage 51, together with the buffer part 55 that is attached to it, is moved against the stop 62 by way of the cable 7. By further tightening the crane cable 71, the diesel hammer 1 is thereby raised about the axis of the roller body 22, wherein the diesel hammer 1 is horizontally rolled in the direction of the crane cable 71 by way of the roller body 22. The tensile force introduced by way of the cable 7 is exclusively directed at the stop 62, by way of which raising of the diesel hammer 1 takes place. In this way, impairment of the guide spars 21 or also of the disengagement apparatus 5 is prevented.

After the diesel hammer has been raised, it is set onto the material to be pile-driven, wherein the pile ram chisel 4 encloses the material to be pile-driven on its end side. Subsequently, the crane cable is relaxed, thereby moving the two ends of the cable 7, with the disengagement apparatus 5 attached to the cable in the direction of the pile ram chisel 4 due to the force of gravity, until the entrainment hook—not shown—of the disengagement apparatus engages into a piston—not shown—situated within the cylinder 2. By pulling in the crane cable, the disengagement apparatus 5 is pulled upward by way of the cable 7, until the disengagement position is reached, whereupon the piston—not shown—is released. In this position, the buffer part is positioned at a distance from the stop 62, so that the diesel hammer is not raised by the crane cable.

Although only a few embodiments of the present invention have been shown and described, it is to be understood that many changes and modifications may be made thereunto without departing from the spirit and scope of the invention. 

What is claimed is:
 1. A pile hammer comprising: (a) a cylinder having an interior; (b) a stop disposed on the cylinder and projecting outward from the cylinder; (c) a piston displaceably guided in the cylinder and having a piston face surface; (d) a striker displaceably guided in the cylinder and disposed underneath the piston in an operating position, said striker having a striker face surface lying in the interior of the cylinder; (e) a combustion chamber delimited axially by the striker face surface and by the piston face surface; (f) a disengagement apparatus for moving the piston in the cylinder into an upper position, said disengagement apparatus comprising at least one cable and a carriage connected with the at least one cable for guiding the carriage to be displaceable along an outside portion of the cylinder and a buffer part disposed on the carriage, said buffer part lying against the stop in an upper end position.
 2. The pile hammer according to claim 1, wherein the at least one cable is guided between at least one pair of guide rollers disposed on the cylinder.
 3. The pile hammer according to claim 1, further comprising a leader attached to the cylinder and comprising at least one pair of guide rollers, wherein the at least one cable is guided between the at least one pair of guide rollers.
 4. The pile hammer according to claim 3, wherein the guide rollers of the at least one pair of guide rollers have axes disposed on a line parallel to a center axis of the cylinder.
 5. The pile hammer according to claim 4, wherein the guide rollers of the at least one pair of guide rollers are disposed and dimensioned so that in a vertical position of the cylinder, the at least one cable, in a tensed state, is offset toward the center axis of the cylinder.
 6. The pile hammer according to claim 5, wherein the at least one cable runs through the guide rollers of the at least one pair of guide rollers, in the tensed state, on an extended center axis of the cylinder.
 7. The pile hammer according to claim 1, further comprising a guide anchor disposed on the carriage, first and second pairs of guide rollers disposed on the cylinder, or on a leader attached to the cylinder, at a distance from one another, and first and second cables passing around the guide anchor and guided on first and second sides of the guide anchor between two guide rollers of the first and second pairs of guide rollers, respectively.
 8. The pile hammer according to claim 7, wherein the guide rollers of the first and second pairs of guide rollers have a radially circumferential guide groove, in each instance, to accommodate the first and second cables, respectively, wherein the groove aligns with a guidance of the guide anchor.
 9. The pile hammer according to claim 8, wherein the guide anchor is disposed orthogonal to a longitudinal center axis of the carriage.
 10. The pile hammer according to claim 1, wherein the buffer part is configured to be elastic, at least in certain regions.
 11. The pile hammer according to claim 1, wherein the buffer part is elastically mounted on the carriage.
 12. The pile hammer according to claim 7, wherein each cable that runs around the guide anchor is connected with a traverse at two ends of the respective cable, wherein the traverse is provided with an accommodation for a crane cable.
 13. The pile hammer according to claim 12, wherein the accommodation is formed by a shackle for accommodating a crane hook.
 14. The pile hammer according to claim 1, wherein the stop has a contact piece that projects beyond the carriage.
 15. The pile hammer according to claim 14, further comprising a first end and a second end opposite the first end, wherein the carriage is disposed on the first end and a contact part is disposed on the second end parallel to the contact piece.
 16. The pile hammer according to claim 15, wherein the contact part is a roller body. 